Complex-shaped Tall Buildings Research Articles

Diagrid Systems for Structural Design of Complex-Shaped Tall Buildings

Today's architectural design trend based on the recognition of pluralism has led to multiple design directions for all building types including tall buildings. This contemporary design trend has produced many complex-shaped tall buildings, such as twisted, tilted, tapered and freeform towers. Among many different structural systems developed for tall buildings, the diagrid system, with its powerful structural rationale and distinguished aesthetic potential, is one of the most widely used systems for today's tall buildings. This paper studies structural performance of diagrid systems employed for complex-shaped tall buildings. Twisted, tilted, tapered and freeform tall buildings are designed with diagrid structures, and their structural performances are investigated. For the twisted diagrid study, the buildings are twisted up to 3 degrees per floor. In the tilted diagrid study, the angles of tilting range from 0 to 13 degrees. The impact of eccentricity is investigated for gravity as well as lateral loads in tilted towers. In the study of tapered diagrid structures, the angles of tapering range from 0 to 3 degrees. In the study of freeform diagrid structures, lateral stiffness of freeform diagrids is evaluated depending on the degree of fluctuation of free form. The freeform floor plans fluctuate from plus/minus 1.5 meter to plus/minus 4.5 meter boundaries of the original square floor plan. Parametric structural models are generated using appropriate computer programs and the models are exported to structural engineering software for design, analyses and comparative studies.

Outrigger Systems for Structural Design of Complex-Shaped Tall Buildings

Outrigger Systems for Structural Design of Complex-Shaped Tall Buildings

층경사각에 의한 횡변위를 고려한 비정형 고층건물의 횡변위 평가/보정

비정형 고층건물의 경우 편심중력하중에 의해 횡변위가 발생한다. 일반해석은 완공시점에 건물 조건을 기준으로 모든 하중을 고려하기 때문에, 시공중 부재 수직도 확보를 통해 각 단계별 보정량을 반영할 수 없어 골조자중에 의한 횡변위를 과대평가한다. 시공단계해석은 통상적인 시공과정에서 각 층마다 바닥평활도 및 기둥/벽체 수직도를 확보하는 것을 고려하여 타설이전에 발생하는 변형각을 보정하기 때문에 일반해석의 한계를 보완할 수 있다. 또한 계측을 통해 타설시점의 좌표를 설계좌표점으로 시공할 경우 각 시공단계에서 추가적인 횡변위보정(원점보정)이 가능하다. 횡변위는 고층부로 갈수록 급격히 증가하므로, 이러한 사전해석을 통해 합리적인 보정계획 수립이 가능하며, 이러한 보정에도 횡변위 관리기준를 초과하는 경우는 선보정 계획을 수립하여야 한다. 이때 사전해석의 불확실성 측면을 고려하여 선보정량을 결정하고, 실제 건물거동의 모니터링을 통해 선보정계획을 지속적으로 수정하여 건물수직도를 확보할 필요가 있다.

Structural Design and Construction of Complex-Shaped Tall Buildings

Today's diverse architectural design trends have produced tall buildings of various forms, such as twisted, tilted, and free forms, as can be seen in the Infinity Tower in Dubai, Veer Towers in Las Vegas and Phare Tower project in Paris. This paper studies various structural system design options for these complex-shaped tall buildings and their performances. For each complex form category, tall buildings are designed with different contemporary structural systems, such as diagrids, braced tubes and outrigger systems. The structural efficiency of each system, in conjunction with building forms, heights and height-to-width aspect ratios, is studied. Parametric structural models are generated to investigate the impacts of variation of important geometric configurations of complex-shaped tall buildings. The models are then exported to structural engineering software for analyses and design. Based on the study results, comparative structural efficiency of different structural systems for tall buildings of each complex form category is estimated.

COMPARATIVE EFFICIENCY BETWEEN STRUCTURAL SYSTEMS FOR COMPLEX-SHAPED TALL BUILDINGS

This paper presents various structural system design options for complex-shaped tall buildings—such as twisted, tilted, and freeform tall buildings—and evaluates their comparative structural efficiency. For each complex form category, tall buildings are designed with different contemporary tall building structural systems, e.g., diagrids, braced tubes, and outrigger systems. Comparative structural efficiency between these systems in conjunction with building forms and height is studied. The heights of the studied buildings range from 60 to 100 stories, and the corresponding height-to-width aspect ratios range from 6.5 to 10.8. Parametric structural models are generated with Rhino/Grasshopper to investigate the impacts of various important geometric configurations of complex-shaped tall buildings, such as the rate of twist, angle of tilt, and degree of fluctuation of free form. The parametric models are exported to structural engineering software SAP2000 for analyses and design. Based on the study results, comparative structural efficiency between different structural systems of each complex form category is presented.

비틀림 초고층 프로토타입 모델에 대한 시공단계해석의 적용

Abstract With regard to complex-shaped tall buildings whose plans and constructions have been gradually on the increase, this study was aimed to analyze their structural behaviors during construction by applications of construction sequences analyses to prototype models. For twisted tall buildings, total 18 models of with three conditions of a lateral load-resisting system, a twisting angle, and a construction method were selected. A diagrid system and a braced tube system were applied as a lateral load-resisting system. For each lateral load-resisting system, three types of plan with 0, 1, and 2twisting angles and three construction methods with construction sequences of exterior tube and interior frame were assumed. The structural performances of tall buildings under constructions were analyzed with results of lateral displacements from construction sequence analyses. Also, construction performances of the construction period and the maximum lift weight were compared. Keywords :tall building, complex-shape, construction sequence analysis, construction, twisted shapes

Diagrid Structures for Complex-Shaped Tall Buildings

Diagrid structures are widely used for today’s tall buildings due to their distinguished architectural aesthetics in any existing urban context and structural efficiency in carrying lateral loads. With prevalent emergence of complex-shaped buildings throughout the world, this paper investigates structural efficiency of diagrid structures employed for complex-shaped tall buildings, such as twisted, tilted and freeform towers. For each complex form category, tall buildings are designed with diagrid systems, and their structural efficiency is studied in conjunction with building forms. In order to investigate the impacts of various important geometric configurations of complex-shaped tall buildings, parametric models are generated using appropriate computer programs, and the models are exported to structural engineering software for design and analyses. Based on the study results, structural efficiency of diagrids for tall buildings of each complex form category is estimated.

Diagrid Structures for Complex-Shaped Tall Buildings

Diagrid structures are widely used for today’s tall buildings due to their distinguished architectural aesthetics in any existing urban context and structural efficiency in carrying lateral loads. With prevalent emergence of complex-shaped buildings throughout the world, this paper investigates structural efficiency of diagrid structures employed for complex-shaped tall buildings, such as twisted, tilted and freeform towers. For each complex form category, tall buildings are designed with diagrid systems, and their structural efficiency is studied in conjunction with building forms. In order to investigate the impacts of various important geometric configurations of complex-shaped tall buildings, parametric models are generated using appropriate computer programs, and the models are exported to structural engineering software for design and analyses. Based on the study results, structural efficiency of diagrids for tall buildings of each complex form category is estimated.

Braced Tube Structures for Complex-Shaped Tall Buildings

Braced tubes, which carry lateral loads by axial actions of the perimeter columns and bracings, are very efficient structural systems for tall buildings. This paper investigates structural efficiency of braced tube structures employed for complex-shaped tall buildings, such as twisted, tilted and tapered towers. For each complex form category, tall buildings are designed with braced tube systems, and their structural efficiency is studied in conjunction with building forms. In order to investigate the impacts of various important geometric configurations of complex-shaped tall buildings, parametric models are generated using appropriate computer programs, and the models are exported to structural engineering software for design and analyses. Based on the study results, structural efficiency of braced tubes for each complex form category is estimated.

Braced Tube Structures for Complex-Shaped Tall Buildings

Braced Tube Structures for Complex-Shaped Tall Buildings

경사진 다이어그리드 비정형 초고층 건물에 대한 스마트 TMD의 제진성능평가

근래에 들어와서 3T (Twisted, Tapered, Tilted)로 대별되는 비정형 초고층 건축물이 다수 계획되고 있다. 이러한 비정형 초고층 건물을 위해서 구조적인 효율성 및 조형성 때문에 다이어그리드 구조시스템이 현재까지 가장 널리 사용되고 있는 구조시스템 중의 하나이다. 건축적인 조형미 등의 이유로 경사진 비정형 초고층 건물에 대한 계획안이 다수 발표되고 있으며 다수의 구조물들이 다이어그리드 구조시스템을 활용하고 있다. 경사진 비정형 초고층 건물은 횡하중뿐만 아니라 자중에 의해서도 횡방향 변위가 발생한다. 따라서 정형적인 초고층 건물보다 횡방향 응답을 저감시카는 젓이 더 중요한 문제로 대두된다. 본 연구에서는 경사진 다이어그리드 비정형 초고층 건물의 지진응답을 저감시키기 위하여 스마트 TMD를 적용하였고 그 제어성능을 평가하였다. 스마트 TMD를 구성하기 위하여 MR 감쇠기를 사용하였으며 스마트 TMD는 그라운드훅 제어알고리즘을 사용하여 제어하였다. 100 층의 예제구조물에 대하여 제어를 하지 않은 경우와, 일반적인 TMD를 사용한 경우, 그리고 스마트 TMD를 사용하여 제어한 경우를 비교 검토하였다. 수지해석결과 스마트 TMD가 변위 응답 제어에는 우수한 성능을 나타냈지만 가속도응답제어에는 효과적이지 못했다. Recently, complex-shaped tall buildings represented by 3T(Twisted, Tapered, Tilted) are planed largely. A diagrid structural system is one of the most widely used structural system for complex-shaped tall buildings because of its structural efficiency and formativeness. Plans for tilted tall buildings are largely presented because of beauty of a sculpture and many of buildings use diagrid structural systems. Lateral displacements of tilted tall buildings are induced by not only lateral loads but also self weight. Therefore, reduction of lateral responses of tilted tall buildings is as important as typical tall buildings. In this study, a smart TMD is introduced to reduce seismic responses of tilted diagrid tall buildings and its control performance is evaluated. MR damper is employed for the smart TMD and ground-hook controller is used as a control algorithm for the smart TMD. 100-story tall building is used as an example structure. Control performances of uncontrolled case, controlled case with TMD and controlled case with smart TMD are compared and investigated. Numerical simulation has shown that smart TMD presented good control performance for displacement response but acceleration response was not controlled well.

다이어그리드 메가프레임 초고층 건물을 위한 효율적인 해석모델의 개발

Among structural systems for complex-shaped tall buildings, diagrid system is widely used because of its structural efficiency and beauty of form. Recently, mega frame is favorably employed as a suitable structural system for skyscrapers because this structural system has sufficient stiffness against the lateral forces by combination of mega members which consist of many columns and girders. Diagrid mega frame system is expected to be promising structural system for future super tall buildings. However, it takes tremendous analysis times and engineer`s efforts to predict the structural behavior of tall buildings applied with diagrid mega frame system because the diagrid mega frame structure has significant numbers of elements and nodes. Therefore, efficient analytical method for all buildings applied with diagrid mega frame system has been proposed in this study to reduce the efforts and time required for the analysis and design of diagrid mega frame structure. To this end, an efficient modelling technique using the characteristics of diagrid mega frame structures and an efficient analytical model using minimal DOFs by the matrix condensation method were proposed in this study. Based on the analysis of an example structure, the effectiveness and accuracy of the proposed method have been verified by the comparison between the results of the proposed method and the conventional method.

Diagrid Structures for Complex-Shaped Tall Buildings

Diagrid structures are prevalently used for today's tall buildings due to their structural efficiency and architectural aesthetic potentials. This paper studies structural performance of diagrid systems employed for complex-shaped tall buildings such as twisted, tilted and freeform towers. For each complex form category, tall buildings are designed with diagrid systems, and their structural efficiency is studied in conjunction with building forms. In order to investigate the impacts of variation of important geometric configurations of complex-shaped tall buildings, such as the rate of twisting and angle of tilting, parametric structural models are used for this study. Based on the study results, design considerations are discussed for the efficient use of diagrid structures for complex-shaped tall buildings.